I installed 20200731 and it did not configure the 8125b network chip.
The install process could see the intel wifi ax200 chip - which isn’t used on my network - but showed nothing for the ethernet hardware.
Flipping the tab onto the ethernet section of the install page showed nothing that indicated TW was aware of the hardware.
Getting to the desktop after the install predictably resulted in no network access.
I have tried Open Media Vault with kernel 5.4 and it did not work with RTL8125 until a patch was added. I would think an NAS is one case where you would want faster ethernet cards.
There are now more linux distros with newer kernels. openmandriva with kernel 5.5 works with RTL8125. Fedora and Manjaro also have kernel > 5.4, but I don’t have enough cards to try them all. I ordered some more, but freight is so slow with COVID-19
I have the same issue as OP. Network isn’t working, so I transfer files from another computer via USB. I downloaded the driver from RealTek’s website but need certain packages in order to compile it with the kernel until it is included in opensuse. I installed Tumbleweed yesterday which is at version 184.108.40.206. What packages are needed to manually install the driver? The DVD iso did not include a base devel pattern, so I chose make, gcc, etc. I manually installed kernel-source.220.127.116.11-2 but when I try to install the source, it says nothing provides kernel-devel. The package search (https://software.opensuse.org/search?utf8=✓&baseproject=openSUSE%3AFactory&q=kernel-devel) returns no kernel-devel package. I am new to opensuse, so if this is a pattern that needs installing, how is that achieved?